1. Field of the Invention
The present invention relates to a robot control apparatus capable of transferring a workpiece whose parameter exceeds a rated workpiece parameter.
2. Description of the Related Art
Upsizing of an industrial robot for transferring heavyweight workpieces results in a considerable increase in cost for producing the robot. Some conventional apparatuses addressing this problem are known that achieve transfer of heavy objects by reducing the load acting on an industrial robot (for example, refer to Japanese Laid-open Patent Publication No. 61-214983, Japanese Laid-open Patent Publication No. 11-58287, or Japanese Examined Patent Application Publication No. 63-7917). The apparatuses described in these patent documents each include a balancer which is disposed on a ceiling above the industrial robot and is connected to a workpiece gripping unit of the robot so as to absorb the load acting on the robot in the direction of gravitational force.
However, the apparatuses described in the above patent documents result in cost increase due to the need for disposing a balancer on a ceiling.